1. Field of the Invention
The present invention relates generally to x-ray systems, devices, and related components. More particularly, exemplary embodiments of the invention concern cooling systems and components for x-ray imaging systems.
2. Related Technology
The ability to consistently develop high quality radiographic images is an important element in the usefulness and effectiveness of x-ray devices as diagnostic tools. However, various factors relating to the construction and/or operation of the x-ray device often serve to materially compromise the quality of radiographic images generated by the device. Such factors include, among others, and various thermally induced effects such as the occurrence of physical changes in the x-ray device components as a result of high operating temperatures and/or thermal gradients.
The physical changes that occur in the x-ray device components as a result of the relatively high operating temperatures typically experienced by the x-ray device are of particular concern. Not only do the high operating temperatures impose significant mechanical stress and strain on the x-ray device components, but the heat transfer effected as a result of those operating temperatures can cause the components to deform, either plastically or elastically.
While plastic deformation of an x-ray device component is a concern because it may be symptomatic of an impending failure of the component, elastic deformation of the x-ray device components under high heat conditions is problematic as well. For example, as the various components and mechanical joints are subjected to repeated elastic deformation under the influence of thermal cycles, the connections between the components can loosen and the components may become misaligned or separated. In addition, the elastic deformation of x-ray device components has significant implications as well with respect to the performance of the x-ray device.
Accordingly, various cooling systems, components and devices have been considered in an effort to effectively address the problems implicated by the high operating temperatures and thermal cycles typically experienced in x-ray devices and imaging system environments. As discussed below however, typical cooling systems and devices have proven to be problematic.
One purported solution to the thermal problems presented by x-ray devices and imaging systems involves the use of a unified cooling system cabinet that is in fluid communication with the housing of an x-ray tube. Typically, the cooling system cabinet is an integral element of the x-ray tube. That is, the x-ray tube and cooling system cabinet are manufactured and sold together as an integral, replaceable, unit. Often, such integral units are constructed so that the cooling system cabinet serves as a mounting interface that enables mounting of the integral unit to an associated x-ray imaging system. In other cases, major elements of the cooling system, such as heat exchangers and fans, are attached directly to the housing of the x-ray tube, so that no cooling system cabinet is required. While cooling systems such as those just described may be able to provide useful thermal effects in some situations, significant problems with this type of integrated approach nonetheless remain.
For example, because the cooling system cabinet and the x-ray tube are manufactured as an integral unit, any defect in any portion of the integral unit, even where the defect may be as minor as a cosmetic scratch on the cooling system cabinet, or a premature failure of a cooling system component, can serve as adequate grounds for rejection of the entire unit, either at the incoming inspection by the manufacturer quality assurance department, or by the end customer. In particular, even if the identified defect(s) could be easily remedied in the field, quality assurance standards typically require that the entire unit be rejected by the manufacturer. In the event that a defect, however minor, is first discovered by the customer, warranty limitations would likewise compel the customer to return the unit to the manufacturer, since most customers are disinclined to take any action that could void a warranty on expensive capital equipment such as x-ray systems and equipment.
In either case, the manufacturer is typically compelled to scrap the entire unit. Clearly, this type of practice results in significant, and typically non-recoverable, expense on the part of the manufacturer.
The same general considerations extend to the unit once it is placed in service. In particular, even if a minor component of the tube or the cooling system should fail, such a failure typically necessitates replacement of the entire integrated tube and cooling system unit. In addition to the significant expense involved in the purchase of a replacement unit, service personnel time and shipping costs must also be considered. As well, the replacement of the entire unit in such situations results in the waste of the other remaining components of the unit, notwithstanding that such components may still be fully functional and operational. Further, replacement of the entire unit also increases system down time.
Yet another concern with integral units that include both a cooling system cabinet and x-ray tube relates to the relative differences in the respective service lives of components of the integral unit. By way of example, it is sometimes the case that a cooling fan located in the cooling system cabinet has a relatively shorter service life than other components of the integral unit. As a result, the life of the unit as a whole is largely dictated by the expected life of the fan, or the life of whichever other component(s) are most likely to fail first.
In view of the foregoing, and other, problems in the art, it would be useful to provide an x-ray imaging system that includes a modular cooling unit. Exemplary embodiments of the modular cooling unit should be configured and arranged so that constituent components of the modular cooling system can be readily removed and replaced without necessitating the replacement of the x-ray tube insert and housing, or other system components. In addition, such embodiments of the modular cooling unit should be constructed and implemented so as to allow for relative differences in the service lives of elements of the x-ray imaging system.